1. Field of the Invention
The present invention relates to a recording and/or reproducing apparatus. More particularly, the present invention relates to a recording and/or reproducing apparatus which can record and/or reproduce data of a program such as a musical piece onto or from a recording medium such as a disc.
2. Description of the Related Art
A compact disc (CD), which is an exemplary one of conventionally known optical discs, has recorded on an inner circumference side thereof information of contents of the disc called TOC (table of contents) data.
The contents information includes the number of musical pieces recorded on the disc, a total playing time and playing times of the individual musical pieces. A recording and/or reproducing apparatus wherein an elapsed time, a remaining time and a remaining number of musical pieces obtained from such contents information are displayed on a display unit is already known and disclosed, for example, in Japanese Laid-Open Utility Model Gazette No. 63 113289.
Also a recordable optical disc wherein an accumulated recording time is recorded in a user TOC (table of contents) area is already known and disclosed, for example, in U.S. Pat. No. 5,111,442.
Another recordable disc wherein a recordable area thereon can be calculated from the TOC information thereon is already known and disclosed, for example, in U.S. Pat. No. 4,862,439.
Recordable disc-shaped media such as, for example, magneto-optical discs provide random accessing compared with tape-formed recording media such as digital audio tapes and compact cassette tapes.
Accordingly, for example, a program need not necessarily be recorded on a continuous segment of a recordable disc medium but may be recorded discretely on a plurality of segments on the disc. In this instance, if the read-in transfer rate of the reproduction data of the disc is raised and the reproduction data is reproduced after it is stored once into a RAM (random access memory), then the data can be reproduced without trouble. It is to be noted that a segment herein denotes a portion of a track in which data is recorded physically and continuously on a disc.
In short, when segment data recorded at positions spaced from each other on a disc are to be linked, if it is possible to access the position at which the segment data to follow the preceding segment data is recorded, at such a high rate that, while the preceding segment data is read out from the RAM, accessing to the following segment data is completed to prepare for reproduction of the following segment data, there is no trouble in recording/reproduction of data even if a track of one program is physically divided into a plurality of discrete segments. A recording and/or reproducing apparatus wherein the transfer rate at which data is read out is sufficiently high and data thus read out is stored once into a RAM and then read out from the RAM at an ordinary read-out rate is disclosed, for example, in U.S. patent application Ser. No. 717,700, filed Jun. 19, 1991.
A disc on which data are recorded discretely is illustratively shown in FIG. 7. Referring to FIG. 7, data of a first musical piece and data of a second musical piece are recorded continuously on a segment T1 and another segment T2, respectively. However, it is otherwise possible to record data of a musical piece separately on discontinuous segments on a track in such a manner that data of fourth and fifth programs are recorded divisionally on discontinuous segments T4(1) to T4(4) and T5(1) to T5(2), respectively, as shown in FIG. 7. It is to be noted that FIG. 7 shows the disc only in a schematic fashion, and actually, in most cases one segment is recorded spirally over several to several hundreds circumferences.
When recording or erasure of a program onto or from a magneto-optical disc is repeated, empty areas are produced irregularly on tracks of the disc due to a difference between playing times of recorded programs or between playing times of erased programs. However, if such discrete recording is performed, then it is possible to record, for example, a program longer than another program erased from the disc onto the disc making use of the portion from which the program has been erased. Consequently, it can be prevented that a useless data recording area is produced by a repetition of recording and/or erasure. It is to be noted that, in the present specification, a mass of data continuous in contents is represented as "program". Here, the program is not limited to musical information but may include any audio signals.
In a disc medium of the type described above, in order to allow random accessing, data for linking segments (for example, T4(1) to T4(4) in FIG. 7) of a program are stored as user TOC information which is re-written each time a recording operation or an erasing operation is performed. Thus, a recording and/or reproducing apparatus is controlled so as to read the user TOC information and perform accessing of a head to achieve an appropriate recording and/or recording operation. An exemplary one of signal recording and/or reproducing apparatus of the type just described is disclosed in U.S. patent application Ser. No. 945,488, filed Sep. 16, 1992.
By the way, in a recording medium in the form of a disc which allows recording of a program or the like thereon by a user, it is convenient if the remaining time available for recording and the number of recordable programs by a user, a playing time of each program recorded on the disc and so forth are calculated and displayed on a display unit.
However, since a track is not always recorded continuously (in short, in one segment), there is a problem in that the recording time from a last one of the already recorded tracks to a last one of recordable tracks cannot be determined merely as a recordable remaining time.